A single identifier, such as an internet protocol (IP) address, can be used both to identify a networked device and to locate a device topologically in the network. The use of this single IP address is not an optimal solution, because optimization with respect to routing conflicts with optimization with respect to topology. Specifically, to efficiently route traffic, addresses should be assigned topologically. However, to effectively manage addressing without the need to reroute in response to changes in location, addresses should explicitly not be tied to topology.
RFC 6830 of the Internet Engineering Task Force (IETF) proposes a “Location/Identifier Separation Protocol” (LISP), which proposes functions that routers may use to map from Endpoint Identifiers (EIDs) to routable Routing Locators (RLOCs), where EIDs are not globally routable. EIDs may be in different forms for different implementations of LISP, and several such forms are known in the art. For example, EIDs may look like IPv4 IP addresses, IPv6 IP addresses, or MAC addresses by way of non-limiting example. RLOCs are assigned to first-hop routers servicing a subnetwork, and are used for routing and forwarding packets throughout a larger network. EIDs, in contrast, are assigned to hosts on the subnetwork independent of network topology, and may globally uniquely identify a particular host. However, EIDSs may not be used for routing purposes. Rather, LISP provides methods for mapping between RLOCs and EIDs, and for encapsulating traffic originated by devices using non-routable EIDs for transport across a network infrastructure that routes and forwards using RLOCs.